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Short Introduction
Wolfgang Nentwig
We have plenty of possibilities to manage and control, or prevent and avoid, or
sometimes even to undo or reverse a biological invasion. The first approach in
such a project is usually a discussion on the nature of the means which should
be used. Economists conclude that biological invasions are simply the result of
basic economic principles, and they predict that redefining the rules of the
game will prevent further alien species from spreading or, at least, identify
someone who would pay for any damages (Chap. 20).
Scientists involved in the often frustrating, everyday business of food quarantine
and transportation stowaways have their own ideas about more intensive
inspections (Chap. 21). The new ghost of globalization with unlimited
trade around the globe could stigmatise protective measures as trade impediment.
Is this the end of control possibilities?
In principle, conservation biologists are able to eradicate an invasive alien
species once it has been established. There are, however, narrow limits to such
techniques, making a successful eradication dependent on very specific circumstances
(Chap. 22). In addition, biological control, once considered as a
unique tool to eradicate alien species, initially dispersed even more aliens and
caused more problems than it solved. Today, the situation has completely
changed and modern biocontrol is a valuable tool (Chap. 23). Still, is it realistic
to assume that at least one biological control agent would be available
against each invasive alien species?
Would the precautionary principle not be a more appropriate reaction to
the global threat of biological invasions? This would mean, of course, that
stricter steps are urgently needed to manage the increasing hazard stemming
from biological invasions. Public information and awareness are critical in
this respect, and we certainly need specific education programs for the general
public. The precautionary principle also includes a full spectrum of measures,
from economically based tools to all control and eradication means
suitable. It is easy to set up such long to-do lists but more difficult, and probably
also frustrating, to work for their implementation. This, however, is
exactly what is needed now (Chap. 24).